CALIFORNIA MECHANICAL CODE MATRIX ADOPTION TABLE CHAPTER 9 INSTALLATION OF SPECIFIC APPLIANCES Adopting Agency BSC SFM HCD DSA OSHPD 1 2 1/AC AC SS SS/CC 1 2 3 4 Adopt Entire Chapter X X X X X Adopt Entire Chapter as amended (amended sections listed below) X X X X X CA DPH Adopt only those sections that are listed below X Article/Section 902.0(D) X X X 907.0 X 907.1 X X X 924.1 X X 924.1.1 X X 2010 CALIFORNIA MECHANICAL CODE 163
164 2010 CALIFORNIA MECHANICAL CODE
CHAPTER 9 INSTALLATION OF SPECIFIC APPLIANCES 901.0 Scope. Warm air heating systems, vented decorative appliances, floor furnaces, vented wall furnaces, unit heaters and room heaters shall comply with the general requirements of Chapter 3 of this code, in addition to the requirements of this chapter. 902.0 General. (A) This chapter is applicable primarily to nonindustrial-type gas utilization appliances and installations and, unless specifically indicated, does not apply to industrial-type appliances and installations. Listed gas utilization appliances shall be installed in accordance with their listing and the manufacturer s instructions, or as elsewhere specified in this chapter. Unlisted appliances shall be installed as specified in this part as applicable to the equipment. For additional information concerning particular appliances and accessories, including industrial types, reference can be made to the standards listed in Chapter 17. [NFPA 54:10.1.1] (B) Gas utilization appliances shall not be installed so its combustion, ventilation, and dilution air are obtained only from a bedroom or bathroom unless the bedroom or bathroom has the required volume in accordance with Section 701.2. [NFPA 54:10.1.2] (C) Where the room size in comparison with the size of the appliance is to be calculated, the total volume of the appliance is determined from exterior dimensions and is to include fan compartments and burner vestibules, where used. Where the actual ceiling height of a room is greater than eight (8) feet (2,438 mm), the volume of the room is figured on the basis of a ceiling height of eight (8) ft. (2,438 mm). [NFPA 54:10.1.3] (D) [OSHPD 1, 2 & 4] Warm air furnaces shall not be installed under openable windows on exterior walls. 902.1 Added or Converted Appliances. When additional or replacement appliances or equipment are installed or an appliance is converted to gas from another fuel, the location in which the appliances or equipment are to be operated shall be checked to verify the following: (A) Air for combustion and ventilation is provided where required, in accordance with the provisions of Chapter 7. Where existing facilities are not adequate, they shall be upgraded to meet Chapter 7 specifications. (B) The installation components and appliances meet the clearances to combustible material provisions of this code. It shall be determined that the installation and operation of the additional or replacement appliances do not render the remaining appliances unsafe for continued operation. (C) The venting system is constructed and sized in accordance with the provisions of Chapter 8. Where the existing venting system is not adequate, it shall be upgraded to comply with Chapter 8. [NFPA 54:9.1.2] 902.2 Type of Gas(es). It shall be determined whether the appliance has been designed for use with the gas to which it will be connected. No attempt shall be made to convert the appliance from the gas specified on the rating plate for use with a different gas without consulting the installation instruction, the serving gas supplier, or the appliance manufacturer for complete instructions. [NFPA 54:9.1.3] 903.0 Air-Conditioning Appliances (Gas-Fired Air Conditioners and Heat Pumps). 903.1 Independent Gas Piping. Gas piping serving heating gas utilization appliances shall be permitted to also serve cooling appliances where heating and cooling appliances cannot be operated simultaneously (See Section 1309.4). [NFPA 54:10.2.1] 903.2 Connection of Gas Engine-Powered Air Conditioners. To protect against the effects of normal vibration in service, gas engines shall not be rigidly connected to the gas supply piping. [NFPA 54:10.2.2] 903.3 Clearances for Indoor Installation. The installation of air-conditioning appliances shall comply with the following requirements: (A) Listed air-conditioning appliances installed in rooms that are large in comparison with the size of the appliance shall be installed with clearances per the terms of their listing and the manufacturer s instructions. (B) Air-conditioning appliances installed in rooms that are NOT large (such as alcoves and closets) in comparison with the size of the equipment shall be listed for such installations and installed in accordance with the manufacturer s instructions. Listed clearances shall not be reduced by the protection methods described in Table 5-3, regardless of whether the enclosure is of combustible or noncombustible material. (C) Unlisted air-conditioning appliances shall be installed with clearances from combustible material of not less than eighteen (18) inches (457 mm) above the appliance and at the sides, front, rear, and nine (9) inches (229 mm) from the draft hood. (D) Air-conditioning appliances (listed and unlisted) installed in rooms that are large in comparison with the size of the appliances shall be permitted to be installed with reduced clearances to combustible material provided the combustible material or appliance is protected as described in Table 5-3 (See 5-3(2)). (E) Where the furnace plenum is adjacent to plaster on metal lath or noncombustible material attached to combustible material, the clearance shall be measured to the surface of the plaster or other noncombustible finish where the clearance specified is two (2) inches (50 mm) or less. (F) Listed air-conditioning appliances shall have the clearance from supply ducts within three (3) feet (914 mm) 2010 CALIFORNIA MECHANICAL CODE 165
of the furnace plenum be not less than that specified from the furnace plenum. No clearance is necessary beyond this distance. [NFPA 54:10.2.3] 903.4 Assembly and Installation. Air-conditioning appliances shall be installed in accordance with the manufacturer s instructions. Unless the appliance is listed for installation on a combustible surface, such as a floor or roof, or unless the surface is protected in an approved manner, it shall be installed on a surface of noncombustible construction with noncombustible material and surface finish and with no combustible material against the underside thereof. [NFPA 54:10.2.4] 903.5 Furnace Plenums and Air Ducts. A furnace plenum supplied as a part of the air-conditioning appliance shall be installed in accordance with the manufacturer's instructions. Where a furnace plenum is not supplied with the appliance, any fabrication and installation instructions provided by the manufacturer shall be followed. The method of connecting supply and return ducts shall facilitate proper circulation of air. [NFPA 54:10.2.5] 903.6 Refrigeration Coils (See Sections 904.7 and 904.8). [NFPA 54:10.2.6] 903.7 Switches in Electrical Supply Line. Means for interrupting the electrical supply to the air-conditioning appliance and to its associated cooling tower (if supplied and installed in a location remote from the air conditioner) shall be provided within sight of and not over fifty (50) feet (15 m) from the air-conditioner and cooling tower. [NFPA 54:10.2.7] 904.0 Central Heating Boilers and Furnaces. 904.1 Location. Central heating furnace and low-pressure boiler installations in bedrooms or bathrooms shall comply with one of the following: (1) Central heating furnaces and low-pressure boilers may be installed in a closet located in the bedroom or bathroom, provided the closet is equipped with a listed, gasketed door assembly and a listed, self-closing device. The self-closing door assembly shall meet the requirements of Section 904.1.1. The door assembly shall be installed with a threshold and bottom door seal and shall meet the requirements of Section 904.1.2. All combustion air for such installations shall be obtained from the outdoors. The closet shall be for the exclusive use of the central heating furnace or low-pressure boiler. (2) Central heating furnaces and low-pressure boilers shall be of the direct-vent type. [NFPA 54:10.3.1] 904.1.1 Self-Closing Doors. Self-closing doors shall swing easily and freely and shall be equipped with a selfclosing device to cause the door to close and latch each time it is opened. The closing mechanism shall not have a hold-open feature. [NFPA 80:6.1.4.2.1, 6.1.4.2.2] 904.1.2 Gasketing. Gasketing on gasket doors or frames shall be furnished only in accordance with the published listings of the door, frame, or gasketing material manufacturer. [NFPA 80:6.4.8] Exception: Where acceptable to the Authority Having Jurisdiction, gasketing of noncombustible or limitedcombustible material (See NFPA 220, Standard on Types of Building Construction) shall be permitted to be applied to the frame, provided closing and latching of the door are not inhibited. 904.2 Clearance. (A) Listed central heating furnaces and low-pressure boilers installed in rooms that are large in comparison with the size of the appliance shall be installed with clearances per the terms of their listings and the manufacturer s instructions (See Sections 208.0 and 1004.0 for definition). [NFPA 54:10.3.2.1] (B) Central-heating furnaces and low-pressure boilers installed in rooms that are NOT large (such as alcoves and closets) in comparison with the size of the appliance shall be listed for such installations. Listed clearances shall not be reduced by the protection methods described in Table 5-3 and illustrated in Figures 9-1(a) through 9-1(c), regardless of whether the enclosure is of combustible or noncombustible material. [NFPA 54:10.3.2.2] (C) Unlisted central-heating furnaces and low pressure boilers installed in rooms that are large in comparison with the size of the appliance shall be installed with clearances not less than those specified in Table 9-1. [NFPA 54:10.3.2.3] (D) Central-heating furnaces and low-pressure boilers (listed and unlisted) installed in rooms that are large in comparison with the size of the appliance shall be permitted to be installed with reduced clearances to combustible material provided the combustible material or appliance is protected as described in Table 5-3. [NFPA 54:10.3.2.4] (E) Front clearance shall be sufficient for servicing the burner and the furnace or boiler. [NFPA 54:10.3.2.5] (F) Where the furnace plenum is adjacent to plaster on metal lath or noncombustible material attached to combustible material, the clearance shall be measured to the surface of the plaster or other noncombustible finish where the clearance specified is two (2) inches (50 mm) or less. [NFPA 54:10.3.2.6] (G) The clearance to these appliances shall not interfere with combustion air, draft hood clearance and relief, and accessibility for servicing (See Sections 304, 701.0, and 802.12.7). [NFPA 54:10.3.2.7] (H) Listed central heating furnaces shall have the clearance from supply ducts within three (3) feet (914 mm) of the furnace plenum be not less than that specified from the furnace plenum. No clearance is necessary beyond this distance. [NFPA 54:10.3.2.8] (I) Unlisted central heating furnaces with temperature limit controls that cannot be set higher than 250 F (121 C) shall have the clearance from supply duct within six (6) feet (1,829 mm) of the furnace plenum be not less than six (6) inches (150 mm). No clearance is necessary beyond this distance. [NFPA 54:10.3.2.9] (J) Central-heating furnaces other than those listed in 904.2 (h) or (i) shall have clearances from the supply ducts of not less than eighteen (18) inches (457 mm) from the furnace plenum for the first three (3) feet (914 mm), then 166 2010 CALIFORNIA MECHANICAL CODE
installation of specific appliances Notes: A equals the clearance with no protection. B equals the reduced clearance permitted. The protection applied to the construction using combustible material shall extend far enough in each direction to make C equal to A. Figure 9-1(a) extent of Protection necessary to reduce clearance From gas equipment or Vent connectors. [nfpa 54-09: Figure 10.3.2.2(a)] six (6) inches (150 mm) for the next three (3) feet (914 mm) and one (1) inch (25 mm) beyond six (6) feet (1,829 mm). [NFPA 54:10.3.2.10] 904.3 Assembly and Installation. A central-heating boiler or furnace shall be installed in accordance with the manufacturer s instructions and shall be installed on a floor of noncombustible construction with noncombustible flooring and surface finish and with no combustible material against the underside thereof, or on fire-resistive slabs or arches having no combustible material against the underside thereof. Exceptions: (1) Appliances listed for installation on a combustible floor. (2) Installation on a floor protected in an approved manner. [NFPA 54:10.3.3] 904.3.1 Under-floor Installation. Furnaces installed in an under-floor area of the building shall comply with the Sections 904.3.1.1 through 904.3.1.3. 904.3.1.1 Supported by Ground. Where a furnace is supported by the ground, it shall be installed on a concrete slab not less than three (3) inches (76 mm) above the adjoining ground level. 904.3.1.2 Supported from Above. Where a furnace is supported from above, a minimum clearance of six (6) inches (152 mm) shall be provided from finished grade. 904.3.1.3 Excavation. Where excavation is necessary to install a furnace, it shall extend to a depth of six (6) inches (152 mm) below and twelve (12) inches (300 mm) on all sides of the furnace, except on the service side, which shall have thirty (30) inches (762 mm). If the depth of the excavation for either the furnace or passageway exceeds twelve (12) inches (300 mm), walls shall be lined with concrete or masonry four (4) inches (102 mm) above the adjoining ground level. 904.4 Temperature- or Pressure-Limiting Devices. Steam and hot water boilers, respectively, shall be provided with approved automatic limiting devices for shutting down the burner(s) to prevent boiler steam pressure or boiler water temperature from exceeding the maximum allowable working pressure or temperature. Safety limit controls shall not be used as operating controls. [NFPA 54:10.3.4] 904.5 Low-Water Cutoff. Hot water boilers installed above the radiation level and all steam boilers shall be provided with an automatic means to shut off the fuel supply to the burner(s) if the boiler water level drops to the lowest safe water line. [NFPA 54:10.3.5] 904.6 Steam Safety and Pressure-Relief Valves. Steam and hot water boilers shall be equipped, respectively, with listed or approved steam safety or pressure-relief valves of appropriate discharge capacity and conforming with ASME requirements. A shutoff valve shall not be placed between the relief valve and the boiler or on discharge pipes between such valves and the atmosphere. (1) Relief valves shall be piped to discharge near the floor. (2) The entire discharge piping shall be at least the same size as the relief valve discharge piping. (3) Discharge piping shall not contain a threaded end connection at its termination point. [NFPA 54:10.3.6] 904.7 Furnace Plenums and Air Ducts. (A) Furnace plenums and air ducts shall be installed in accordance with NFPA 90A, Standard for the Installation of Air-Conditioning and Ventilating Systems, or NFPA 90B, Standard for the Installation of Warm-Air Heating and Air-Conditioning Systems. [NFPA 54:10.3.7.1] (b) A furnace plenum supplied as a part of a furnace shall be installed in accordance with the manufacturer's instructions. [NFPA 54:10.3.7.2] (C) Where a furnace plenum is not supplied with the furnace, any fabrication and installation instructions provided by 2010 california mechanical code 167
installation of specific appliances Masonry walls can be attached to combustible walls using wall ties. Spacers should not be used directly behind appliance or connector. Figure 9-1(b) Wall Protector clearance reduction system. [nfpa 54-09: Figure 10.3.2.2(b)] Figure 9-1(c) masonry clearance reduction system. [nfpa 54-09: Figure 10.3.2.2(c)] the manufacturer shall be followed. The method of connecting supply and return ducts shall facilitate proper circulation of air. [NFPA 54:10.3.7.3] (D) Where a furnace is installed so supply ducts carry air circulated by the furnace to areas out-side the space containing the furnace, the return air shall also be handled by a duct(s) sealed to the furnace casing and terminating outside the space containing the furnace. [NFPA 54:10.3.7.4] 904.8 Refrigeration Coils. The installation of refrigeration coils shall comply with the following requirements: [NFPA 54:10.3.8] (A) A refrigeration coil shall not be installed in conjunction with a forced-air furnace where circulation of cooled air is provided by the furnace blower, unless the blower has sufficient capacity to overcome the external static resistance imposed by the duct system and cooling coil and the air throughput necessary for heating or cooling, whichever is greater. [NFPA 54:10.3.8(1)] (b) Furnaces shall not be located upstream from cooling units, unless the cooling unit is designed or equipped so as not to develop excessive temperature or pressure. [NFPA 54:10.3.8(2)] (C) Refrigeration coils shall be installed in parallel with or on the downstream side of central furnaces to avoid condensation in the heating element, unless the furnace has been specifically listed for downstream installation. With a parallel flow arrangement, the dampers or other means used to control flow of air shall be sufficiently tight to prevent any circulation of cooled air through the furnace. [NFPA 54:10.3.8(3)] (D) Means shall be provided for disposal of condensate and to prevent dripping of condensate on the heating element. [NFPA 54:10.3.8(4)] 904.9 Cooling Units Used with Heating boilers. (A) Boilers, where used in conjunction with refrigeration systems, shall be installed so that the chilled medium is piped in parallel with the heating boiler with appropriate valves to prevent the chilled medium from entering the heating boiler. [NFPA 54:10.3.9.1] (b) Where hot-water-heating boilers are connected to heating coils located in air-handling units where they can be exposed to refrigerated air circulation, such boiler piping systems shall be equipped with flow control valves or other automatic means to prevent gravity circulation of the boiler water during the cooling cycle. [NFPA 54:10.3.9.2] 904.10 Access to Appliances on Roofs. 904.10.1 Appliances located on roofs or other elevated locations shall be accessible. [NFPA 54-09:9.4.3.1] 904.10.2 Buildings of more than fifteen (15) feet (4,572 mm) in height shall have an inside means of access to the roof, unless other means acceptable to the Authority Having Jurisdiction are used. [NFPA 54-09:9.4.3.2] 904.10.3 The inside means of access shall be a permanent or foldaway inside stairway or ladder, terminating in an enclosure, scuttle, or trapdoor. Such scuttles or trapdoors shall be at least twenty-two (22) 168 2010 california mechanical code
inches x twenty-four (24) inches (560 mm x 610 mm) in size, shall open easily and safely under all conditions, especially snow, and shall be constructed so as to permit access from the roof side unless deliberately locked on the inside. At least six (6) feet (1,829 mm) of clearance shall be available between the access opening and the edge of the roof or similar hazard, or rigidly fixed rails or guards a minimum of forty-two (42) inches (1,067 mm) in height shall be provided on the exposed side. Where parapets or other building structures are utilized in lieu of guards or rails, they shall be a minimum of forty-two (42) inches (1,067 mm) in height. [NFPA 54-09:9.4.3.3] 904.11 Appliances in Attics and Under-Floor Spaces. 904.11.1 Access. An attic or under-floor space in which an appliance is installed shall be accessible through an opening and passageway at least as large as the largest component of the appliance, and not less than twentytwo (22) inches x thirty (30) inches (560 mm x 760 mm). [NFPA 54-09:9.5.1] 904.11.2 Passageway Height. Where the height of the passageway is less than six (6) feet (1,829 mm), the distance from the passageway access to the appliance shall not exceed twenty (20) feet (6,096 mm) measured along the center line of the passageway. [NFPA 54-09:9.5.1.1] 904.11.3 Passageway. The passageway shall be unobstructed and shall have solid flooring not less than twenty-four (24) inches (610 mm) wide from the entrance opening to the appliance. [NFPA 54:9.5.1.2] 904.11.4 Work Surface. A level working platform or grade surface not less than thirty (30) inches (760 mm) by thirty (30) inches (760 mm) shall be provided in front of the service side of the appliance. [NFPA 54:9.5.2] 904.11.5 Lighting and Convenience Outlet. A permanent 120-volt receptacle outlet and a lighting fixture shall be installed near the appliance. The switch controlling the lighting fixture shall be located at the entrance to the passageway. [NFPA 54:9.5.3] 904.11.6 Furnace (Upright and Horizontal). Upright furnaces may be installed in an attic, furred, or underfloor space more than five (5) feet (1,524 mm) in height, provided the required listings and furnace and duct clearances are observed. Horizontal furnaces may be installed in an attic, furred, or under-floor space, provided the required listings and furnace and duct clearances are observed. 905.0 Clothes Dryers. 905.1 Clearance. The installation of clothes dryers shall comply with the following requirements: [NFPA 54:10.4.1] (A) Listed Type 1 clothes dryers shall be installed with a minimum clearance of six (6) inches (150 mm) from adjacent combustible material. Clothes dryers listed for installation at reduced clearances shall be installed in accordance with their listing. Type 1 clothes dryers installed in closets shall be specifically listed for such installation. [NFPA 54:10.4.1(1)] (B) Listed Type 2 clothes dryers shall be installed with clearances of not less than that shown on the marking plate and in the manufacturer s instructions. Type 2 clothes dryers designed and marked, "For use only in noncombustible locations," shall not be installed elsewhere. [NFPA 54:10.4.19(2)] (C) Unlisted clothes dryers shall be installed with clearances to combustible material of not less than eighteen (18) inches (460 mm). Combustible floors under unlisted clothes dryers shall be protected in an approved manner. [NFPA 54:10.4.1(3)] 905.2 Exhausting to the Outdoors. Type 1 and Type 2 clothes dryers shall be exhausted to the outside air. [NFPA 54:10.4.2] 905.3 Provisions for Makeup Air. (A) Makeup air shall be provided for Type 1 clothes dryers in accordance with the manufacturer s installation instructions. [NFPA 54:10.4.3.1] (B) Provision for makeup air shall be provided for Type 2 clothes dryers, with a minimum free area (See Section 701.6) of one (1) in. 2 (6.5 m 2 ) for each one thousand (1,000) Btu/h (2,200 mm 2 /kw) total input rating of the dryer(s) installed. [NFPA 54:10.4.3.2] 905.4 Exhaust Ducts for Type 1 Clothes Dryers. (A) A clothes dryer exhaust duct shall not be connected into any vent connector, gas vent, chimney, crawl space, attic, or other similar concealed space. [NFPA 54:10.4.4.1] (B) Ducts for exhausting clothes dryers shall not be assembled with screws or other fastening means that extend into the duct and that would catch lint and reduce the efficiency of the exhaust system. [NFPA 54:10.4.4.2] (C) Exhaust ducts shall be constructed of rigid metallic material. Transition ducts used to connect the dryer to the exhaust duct shall be listed for that application or installed in accordance with the clothes dryer manufacturer's installation instructions. [NFPA 54:10.4.4.3] 905.5 Exhaust Ducts for Type 2 Clothes Dryers. (A) Exhaust ducts for Type 2 clothes dryers shall comply with Section 905.4. [NFPA 54:10.4.5.1] (B) Exhaust ducts for Type 2 clothes dryers shall be constructed of sheet metal or other noncombustible material. Such ducts shall be equivalent in strength and corrosion resistance to ducts made of galvanized sheet steel not less than 0.0195 inch (0.5 mm) thick. [NFPA 54:10.4.5.2] (C) Type 2 clothes dryers shall be equipped or installed with lint-controlling means. [NFPA 54:10.4.5.3] (D) Exhaust ducts for Type 2 clothes dryers shall be installed with a minimum clearance of six (6) inches (150 mm) from adjacent combustible material. Where exhaust ducts for Type 2 clothes dryers are installed with reduced clearances, the adjacent combustible material shall be protected in accordance with Table 5-3. [NFPA 54:10.4.5.4] (E) Where ducts pass through walls, floors, or partitions, the space around the duct shall be sealed with noncombustible material. [NFPA 54:10.4.5.5] 2010 CALIFORNIA MECHANICAL CODE 169
(F) Multiple installations of Type 2 clothes dryers shall be made in a manner to prevent adverse operation due to back pressures that might be created in the exhaust systems. [NFPA 54:10.4.5.6] 905.6 Multiple Family or Public Use. All clothes dryers installed for multiple-family or public use shall be equipped with approved safety shutoff devices and shall be installed as specified for a Type 2 clothes dryer under Section 905.5. [NFPA 54:10.4.6] 906.0 Conversion Burners. Installation of conversion burners shall conform to ANSI Z21.8, Standard for Installation of Domestic Gas Conversion Burners. [NFPA 54:10.5] 907.0 Decorative Appliances for Installation in Vented Fireplaces. 907.1 Prohibited Installations. Decorative appliances for installation in vented fireplaces shall not be installed in bathrooms or bedrooms unless the appliance is listed and the bedroom or bathroom has the required volume in accordance with Section 701.2. [NFPA 54:10.6.1] [OSHPD 1, 2 & 4] A vented decorative appliance shall not be located in any hospital, skilled nursing facility, intermediate care facility, or correctional treatment center. 907.2 Installation. A decorative appliance for installation in a vented fireplace shall be installed only in a vented fireplace having a working chimney flue and constructed of noncombustible materials. These appliances shall not be thermostatically controlled. (1) A listed decorative appliance for installation in a vented fireplace shall be installed in accordance with its listing and the manufacturer's instructions. [NFPA 54:10.6.2.1] (2) A decorative appliance for installation in a vented fireplace where installed in a manufactured home shall be listed for installation in manufactured homes. [NFPA 54:10.6.2.2] (3) An unlisted decorative appliance for installation in a vented fireplace shall be installed in a fireplace having a permanent free opening, based on appliance input rating and chimney height, equal to or greater than that specified in Table 9-2. [NFPA 54:10.6.2.3] 907.3 Fireplace Screens. A fireplace screen shall be installed with a decorative appliance for installation in a vented fireplace. [NFPA 54:10.6.3] 908.0 Gas Fireplaces, Vented. 908.1 Prohibited Installations. Vented gas fireplaces shall not be installed in bathrooms or bedrooms unless the appliance is listed and the bedroom or bathroom has the required volume in accordance with Section 701.2. [NFPA 54:10.7.1] Exception: Direct-vent gas fireplaces. 908.2 Installation. The installation of vented gas fireplaces shall comply with the following requirements: (A) Listed vented gas fireplaces shall be installed in accordance with their listing and the manufacturer s instructions and where installed in or attached to combustible material shall be specifically listed for such installation. [NFPA 54:10.7.2(1)] (B) Unlisted vented gas fireplaces shall not be installed in or attached to combustible material. They shall have a clearance at the sides and rear of not less than eighteen (18) inches (460 mm). Combustible floors under unlisted vented gas fireplaces shall be protected in an approved manner. Unlisted appliances of other than the direct-vent type shall be equipped with a draft hood and shall be properly vented in accordance with Chapter 8. Appliances that use metal, asbestos, or ceramic material to direct radiation to the front of the appliance shall have a clearance of thirty-six (36) inches (910 mm) in front and, if constructed with a double back of metal or ceramic, shall be installed with a minimum clearance of eighteen (18) inches (460 mm) at the sides and twelve (12) inches (300 mm) at the rear. [NFPA 54:10.7.2(2)] (C) Panels, grilles, and access doors that are required to be removed for normal servicing operations shall not be attached to the building. [NFPA 54:10.7.2(3)] (D) Direct-vent gas fireplaces shall be installed with the ventair intake terminal in the outdoors and in accordance with the manufacturer s instructions. [NFPA 54:10.7.2(4)] 908.3 Combustion and Circulating Air. Combustion and circulating air shall be provided in accordance with Section 701.0. [NFPA 54:10.7.3] 909.0 Non-Recirculating Direct Gas-Fired Industrial Air Heaters. 909.1 Application. Direct gas-fired industrial air heaters of the non-recirculating type shall be listed in accordance with ANSI Z83.4/CSA 3.7 Non-Recirculating Direct Gas-Fired Industrial Air Heaters. [NFPA 54:10.8.1] 909.2 Prohibited Installations. (A) Non-recirculating direct gas-fired industrial air heaters shall not serve any area containing sleeping quarters. [NFPA 54:10.8.2.1] (B) Non-recirculating direct gas-fired industrial air heaters shall not recirculate room air. [NFPA 54:10.8.2.2] 909.3 Installation. Installation of direct gas-fired industrial air heaters shall comply with the following requirements: (A) Non-recirculating direct gas-fired industrial air heaters shall be installed in accordance with the manufacturer s instructions. [NFPA 54:10.8.3.1] (B) Non-recirculating direct gas-fired industrial air heaters shall be installed only in industrial or commercial occupancies. [NFPA 54:10.8.3.2] (C) Non-recirculating direct gas-fired industrial air heaters shall be permitted to provide fresh air ventilation. [NFPA 54:10.8.3.3] (D) Non-recirculating direct gas-fired industrial air heaters shall be provided with access for removal of burners; 170 2010 CALIFORNIA MECHANICAL CODE
replacement of motors, controls, filters, and other working parts; and for adjustment and lubrication of parts requiring maintenance. [NFPA 54:10.8.3.4] 909.4 Clearance from Combustible Materials. Non-recirculating direct gas-fired industrial air heaters shall be installed with a clearance from combustible materials of not less than that shown on the rating plate and the manufacturer s instructions. [NFPA 54:10.8.4] 909.5 Air Supply. All air to the non-recirculating direct gasfired industrial air heater shall be ducted directly from outdoors. Where outside-air dampers or closing louvers are used, they shall be verified to be in the open position prior to main burner operation. [NFPA 54:10.8.5] 909.6 Atmospheric Vents, Gas Reliefs, or Bleeds. Non-recirculating direct gas-fired industrial air heaters with valve train components equipped with atmospheric vents, gas reliefs, or bleeds shall have their vent lines, gas reliefs, or bleeds lead to a safe point outdoors. Means shall be employed on these lines to prevent water from entering and to prevent blockage from insects and foreign matter. An atmospheric vent line shall not be required to be provided on a valve train component equipped with a listed vent limiter. [NFPA 54:10.8.6] 909.7 Relief Openings. The design of the installation shall include adequate provisions to permit the non-recirculating direct gas-fired industrial air heater to operate at its rated airflow without overpressurizing the space served by the heater by taking into account the structure's designed infiltration rate, properly designed relief openings, or an interlocked powered exhaust system, or a combination of these methods. [NFPA 54:10.8.7] (A) The structure's designed infiltration rate and the size of relief opening(s) shall be determined by approved engineering methods. [NFPA 54:10.8.7.1] (B) Louver or counterbalanced gravity damper relief openings shall be permitted. Where motorized dampers or closeable louvers are used, they shall be proved to be in their open position prior to main burner operation. [NFPA 54:10.8.7.2] 909.8 Purging. Inlet ducting, when used, shall be purged with at least four air changes prior to an ignition attempt. [NFPA 54:10.8.8] 910.0 Recirculating Direct Gas-Fired Industrial Air Heaters. 910.1 Application. Direct gas-fired industrial air heaters of the recirculating type shall be designed certified to be in compliance with the Standard for Recirculating Direct Gas- Fired Industrial Air Heaters, ANSI Z83.18. Unlisted direct gas-fired industrial air heaters of the recirculating type shall not be installed. [NFPA 54:10.9.1] 910.2 Prohibited Installations. (A) Recirculating direct gas-fired industrial air heaters shall not serve any area containing sleeping quarters. [NFPA 54:10.9.2.1] (B) Recirculating direct gas-fired industrial air heaters shall not recirculate room air in buildings that contain flammable solids, liquids, or gases, explosive materials, or substances that can become toxic when exposed to flame or heat. [NFPA 54:10.9.2.2] 910.3 Installation. Installation of direct gas-fired industrial air heaters shall comply with the following requirements: [NFPA 54:10.9.3] (A) Recirculating direct gas-fired industrial air heaters shall be installed in accordance with the manufacturer's instructions. [NFPA 54:10.9.3(1)] (B) Recirculating direct gas-fired industrial air heaters shall be installed only in industrial or commercial occupancies. [NFPA 54:10.9.3(2)] (C) Recirculating direct gas-fired industrial air heaters shall be permitted to provide fresh air ventilation only for the amount that exceeds the minimum ventilation air specified on the heater's rating plate to maintain the combustion level created by the heater in the space being served by the heater below 25 ppm for carbon monoxide, 3 ppm for nitrogen dioxide, and 5000 ppm for carbon dioxide. Where gas-powered fork trucks or other fossil-fueled appliance are utilized in the conditioned space, additional ventilation requirements for the facility must be addressed separately. [NFPA 54:10.9.3(3)] (D) Recirculating direct gas-fired industrial air heaters shall be provided with access for removal of burners; replacement of motors, controls, filters, and other working parts; and for adjustment and lubrication of parts requiring maintenance. [NFPA 54:10.9.3(4)] 910.4 Clearance from Combustible Materials. Recirculating direct gas-fired industrial air heaters shall be installed with a clearance from combustible materials of not less than that shown on the rating plate and the manufacturer's instructions. [NFPA 54:10.9.4] 910.5 Air Supply. Ventilation air to the recirculating direct gas-fired industrial air heater shall be ducted directly from outdoors. Air to the recirculating direct gas-fired industrial air heater in excess of the minimum ventilation air specified on the heater's rating plate shall be taken from the building, ducted directly from outdoors, or a combination of both. Where outside-air dampers or closing louvers are used, they shall be verified to be in the open position prior to main burner operation. [NFPA 54:10.9.5] 910.6 Atmospheric Vents, Gas Reliefs, or Bleeds. Recirculating direct gas-fired industrial air heaters with valve train components equipped with atmospheric vents, gas reliefs, or bleeds shall have their vent lines, gas reliefs, or bleeds lead to a safe point outdoors. Means shall be employed on these lines to prevent water from entering and to prevent blockage from insects and foreign matter. An atmospheric vent line shall not be required to be provided on a valve train component equipped with a listed vent limiter. [NFPA 54:10.9.6] 910.7 Relief Openings. The design of the installation shall include adequate provisions to permit the recirculating direct gasfired industrial air heater to operate at its rated airflow without overpressurizing the space served by the heater by taking into account the structure's designed infiltration rate, properly designed relief openings or an interlocked powered exhaust system, or a combination of these methods. [NFPA 54:10.9.7] 2010 CALIFORNIA MECHANICAL CODE 171
TABLE 9-1 CLEARANCES TO COMBUSTIBLE MATERIAL FOR UNLISTED FURNACES, BOILERS, AND AIR CONDITIONERS INSTALLED IN ROOMS THAT ARE LARGE IN COMPARISON WITH THE SIZE OF APPLIANCES. [NFPA 54: TABLE 10.2.3(a)] MINIMUM CLEARANCE (in.) APPLIANCE ABOVE AND SIDES OF FURNACE PLENUM TOP OF BOILER JACKET SIDES AND REAR FRONT DRAFT HOOD AND BAROMETRIC DRAFT REGULATOR SINGLE-WALL VENT CONNECTOR I Automatically fired, forced air or gravity 6 6 18 6 18 system, equipped with temperature limit control that cannot be set higher than 250 F (121 C) II Automatically fired heating boilers 6 6 6 18 18 18 steam boilers operating at not over fifteen (15) psi (103 kpa) and hot water boilers operating at 250 F (121 C) or less III Central heating boilers and furnaces, other 18 18 18 18 18 18 than in I or II IV Air-conditioning appliance 18 18 18 18 18 18 Note: See Section 903.3 for additional requirements for air-conditioning appliances and Section 904.1 for additional requirements for central heating boilers and furnaces. TABLE 9-2 FREE OPENING AREA OF CHIMNEY DAMPER FOR VENTING FLUE GASES FROM UNLISTED DECORATIVE APPLIANCES FOR INSTALLATION IN VENTED FIREPLACES. [NFPA 54: TABLE 10.6.2.3] MINIMUM PERMANENT FREE OPENING (in. 2 )* CHIMNEY 8 13 20 29 39 51 64 HEIGHT (ft.) APPLIANCE INPUT RATING (Btu/h) 6 7,800 14,000 23,200 34,000 46,400 62,400 80,000 8 8,400 15,200 25,200 37,000 50,400 68,000 86,000 10 9,000 16,800 27,600 40,400 55,800 74,400 96,400 15 9,800 18,200 30,200 44,600 62,400 84,000 108,800 20 10,600 20,200 32,600 50,400 68,400 94,000 122,200 30 11,200 21,600 36,600 55,200 76,800 105,800 138,600 Notes: 1 ft = 0.305 m, 1 in. 2 = 645 mm 2, 1,000 Btu/h = 0.293 kw *The first six (6) minimum permanent free openings (eight (8) in. 2 to fifty-one (51) in. 2 ) correspond approximately to the cross-sectional areas of chimneys having diameters of three (3) in. through eight (8) in., respectively. The sixty four (64) in. 2 opening corresponds to the cross-sectional area of standard eight (8) in. x eight (8) in. chimney tile. (A) The structure's designed infiltration rate and the size of relief opening(s) shall be determined by approved engineering methods. [NFPA 54:10.9.7.1] (B) Louver or counterbalanced gravity relief openings shall be permitted. Where motorized dampers or closeable louvers are used, they shall be proved to be in their open position prior to main burner operation. [NFPA 54:10.9.7.2] 910.8 Purging. Inlet ducting, when used, shall be purged with at least four air changes prior to an ignition attempt. [NFPA 54:10.9.8] 911.0 Duct Furnaces. 911.1 Clearances. The installation of duct furnaces shall comply with the following clearance requirements: (A) Listed duct furnaces shall be installed with clearances of at least six (6) inches (150 mm) between adjacent walls, ceilings, and floors of combustible material and the furnace draft hood. Furnaces listed for installation at lesser clearances shall be installed in accordance with their listings. In no case shall the clearance be such as to interfere with combustion air and accessibility (See Sections 304 and 701.0.). [NFPA 54:10.10.1(1)] (B) Unlisted duct furnaces shall be installed with clearances to combustible material in accordance with the clearances specified for unlisted furnaces and boilers in Table 9-1. Combustible floors under unlisted duct furnaces shall be protected in an approved manner. [NFPA 54:10.10.1(2)] 911.2 Installation of Duct Furnaces. Duct furnaces shall be installed in accordance with the manufacturer s instructions. [NFPA 54-09:10.10.2] 172 2010 CALIFORNIA MECHANICAL CODE
911.3 Access Panels. The ducts connected to duct furnaces shall have removable access panels on both the upstream and downstream sides of the furnace. [NFPA 54:10.10.3] 911.4 Location of Draft Hoods and Controls. The controls, combustion-air inlet, and draft hoods for duct furnaces shall be located outside the ducts. The draft hood shall be located in the same enclosure from which combustion air is taken. [NFPA 54:10.10.4] 911.5 Circulating Air. Where a duct furnace is installed so that supply ducts carry air circulated by the furnace to areas outside the space containing the furnace, the return air shall also be handled by a duct(s) sealed to the furnace casing and terminating outside the space containing the furnace. The duct furnace shall be installed on the positive-pressure side of the circulating air blower. [NFPA 54:10.10.5] 911.6 Duct Furnaces Used with Refrigeration Systems. (A) A duct furnace shall not be installed in conjunction with a refrigeration coil where circulation of cooled air is provided by the blower. Exception: Where the blower has sufficient capacity to overcome the external static resistance imposed by the duct system, furnace, and the cooling coil and the air throughput necessary for heating or cooling, whichever is greater. [NFPA 54:10.10.6.1] (B) Duct furnaces used in conjunction with cooling equipment shall be installed in parallel with or on the upstream side of cooling coils to avoid condensation within heating elements. With a parallel flow arrangement, the dampers or other means used to control the flow of air shall be sufficiently tight to prevent any circulation of cooled air through the unit. Exception: Where the duct furnace has been specifically listed for downstream installation. [NFPA 54:10.10.6.2] (C) Where duct furnaces are to be located upstream from cooling units, the cooling unit shall be so designed or equipped as to not develop excessive temperatures or pressures. [NFPA 54:10.10.6.3] (D) Where a duct furnace is installed downstream of an evaporative cooler or air washer, the heat exchanger shall be constructed of corrosion-resistant materials. Stainless steel, ceramic-coated steel, and an aluminum-coated steel in which the bond between the steel and the aluminum is an iron-aluminum alloy are considered to be corrosion resistant. Air washers operating with chilled water that deliver air below the dew point of the ambient air at the equipment are considered as refrigeration systems. [NFPA 54:9.10.6.4] 911.7 Installation in Commercial Garages and Aircraft Hangars. Duct furnaces installed in garages for more than three motor vehicles or in aircraft hangars shall be of a listed type and shall be installed in accordance with Sections 911.8 and 911.9. [NFPA 54:10.10.7] 911.8 Installation in Commercial Garages. 911.8.1 Parking Structures. Appliances installed in enclosed, basement, and underground parking structures shall be installed in accordance with NFPA 88A, Standard for Parking Structures. [NFPA 54:9.1.11.1] 911.8.2 Repair Garages. Appliances installed in repair garages shall be installed in a detached building or room, separated from repair areas by walls, partitions, floors, or floor-ceiling assemblies that are constructed so as to prohibit the transmission of vapors and having a fire resistance rating of not less than one (1) hour, and that have no openings in the wall separating the repair area within eight (8) feet (2,438 mm) of the floor. Wall penetrations shall be firestopped. Air for combustion purposes shall be obtained from outside the building. The heating room shall not be used for the storage of combustible materials. Exceptions: (1) Overhead heaters where installed not less than eight (8) feet (2,438 mm) above the floor shall be permitted. (2) Heating appliances for vehicle repair areas where there is no dispensing or transferring of Class I or Class II flammable or combustible liquids or liquefied petroleum gas shall be installed in accordance with NFPA 30A, Code for Motor Fuel Dispensing Facilities and Repair Garages. [NFPA 54:9.1.11.2] 911.9 Installation in Aircraft Hangars. Heaters in aircraft hangars shall be installed in accordance with NFPA 409, Standard on Aircraft Hangars. [NFPA 54:9.1.12] 912.0 Floor Furnaces. 912.1 Installation. The installation of floor furnaces shall comply with the following requirements: (A) Listed floor furnaces shall be installed in accordance with their listing and the manufacturer s instructions. (B) Unlisted floor furnaces shall not be installed in combustible floors. (C) Thermostats controlling floor furnaces shall not be located in a room or space that can be separated from the room or space in which the register of the floor furnace is located. [NFPA 54:10.11.1] 912.2 Temperature Limit Controls. (A) Listed automatically operated floor furnaces shall be equipped with temperature limit controls. (B) Unlisted automatically operated floor furnaces shall be equipped with a temperature limit control arranged to shut off the flow of gas to the burner in the event the temperature at the warm-air outlet register exceeds 350 F (177 C) above room temperature. [NFPA 54:10.11.2] 912.3 Combustion and Circulating Air. Combustion and circulating air shall be provided in accordance with Section 701.0. [NFPA 54:10.11.3] 912.4 Placement. The following provisions apply to furnaces that serve one story. (A) Floors. Floor furnaces shall not be installed in the floor of any doorway, stairway landing, aisle, or passageway of any enclosure, public or private, or in an exitway from any such room or space. [NFPA 54:10.11.4(1)] (B) Walls and Corners. The register of a floor furnace with a horizontal warm-air outlet shall not be placed closer 2010 CALIFORNIA MECHANICAL CODE 173
than six (6) inches (150 mm) from the nearest wall. A distance of at least eighteen (18) in. (460 mm) from two adjoining sides of the floor furnace register to walls shall be provided to eliminate the necessity of occupants walking over the warm-air discharge. The remaining sides shall be a minimum of six (6) inches (150 mm) from a wall. Wall-register models shall not be placed closer than six (6) in. (150 mm) to a corner. [NFPA 54:10.11.4(2)] (C) Draperies. The furnace shall be placed so that a door, drapery, or similar object cannot be nearer than twelve (12) inches (300 mm) to any portion of the register of the furnace. [NFPA 54:10.11.4(3)] 912.5 Bracing. The space provided for the furnace shall be framed with doubled joists and with headers not lighter than the joists. [NFPA 54:10.11.5] 912.6 Support. Means shall be provided to support the furnace when the floor register is removed. [NFPA 54:10.11.6] 912.7 Clearance. The lowest portion of the floor furnace shall have at least a six (6) inch (150 mm) clearance from the general ground level. A reduced clearance to a minimum of two (2) inches (50 mm) is permitted, provided the lower six (6) inches (150 mm) portion of the floor furnace is sealed by the manufacturer to prevent entrance of water. Where these clearances are not present, the ground below and to the sides shall be excavated to form a "basin-like" pit under the furnace so that the required clearance is provided beneath the lowest portion of the furnace. A twelve (12) inch (300 mm) clearance shall be provided on all sides except the control side, that shall have an eighteen (18) inch (460 mm) clearance. [NFPA 54:10.11.7] 912.8 Access. The space in which any floor furnace is installed shall be accessible by an opening in the foundation not less than twenty-four (24) inches x eighteen (18) inches (610 mm x 460 mm) or by a trap door not less than twentyfour (24) inches x twenty-four (24) inches (610 mm x 610 mm) in any cross-section thereof, and a passageway not less than twenty-four (24) inches x eighteen (18) inches (610 mm x 460 mm) in any cross-section thereof. [NFPA 54:10.11.8] 912.9 Seepage Pan. Where the excavation exceeds twelve (12) inches (300 mm) in depth or water seepage is likely to collect, a water-tight copper pan, concrete pit, or other suitable material shall be used, unless adequate drainage is provided or the appliance is sealed by the manufacturer to meet this condition. A copper pan shall be made of not less than sixteen (16) oz./ft. 2 (4.9 kg/m 2 ) sheet copper. The pan shall be anchored in place so as to prevent floating, and the walls shall extend at least four (4) inches (100 mm) above the ground level with at least six (6) inches (150 mm) clearance on all sides, except the control side, which shall have at least eighteen (18) inches (460 mm) clearance. [NFPA 54:10.11.9] 912.10 Wind Protection. Floor furnaces shall be protected, where necessary, against severe wind conditions. [NFPA 54:10.11.10] 912.11 Upper-Floor Installations. Listed floor furnaces shall be permitted to be installed in an upper floor, provided the furnace assembly projects below into a utility room, closet, garage, or similar nonhabitable space. In such installations, the floor furnace shall be enclosed completely (entirely separated from the nonhabitable space) with means for air intake to meet the provisions of Section 701.0, with access for servicing, the minimum furnace clearances of six (6) inches (150 mm) to all sides and bottom, and with the enclosure constructed of portland cement plaster or metal lath or other noncombustible material. [NFPA 54:10.11.11] 912.12 First Floor Installation. Listed floor furnaces installed in the first or ground floors of buildings shall not be required to be enclosed unless the basements of these buildings have been converted to apartments or sleeping quarters, in which case the floor furnace shall be enclosed as specified for upper floor installations and shall project into a non-habitable space. [NFPA 54:10.11.12] 913.0 Food Service Appliance, Floor Mounted. 913.1 Clearance for Listed Appliances. Listed floormounted food service appliances, such as ranges for hotels and restaurants, deep-fat fryers, unit broilers, gas-fired kettles, steam cookers, steam generators, and baking and roasting ovens, shall be installed at least six (6) inches (150 mm) from combustible material except that at least a two (2) inch (50 mm) clearance shall be maintained between a draft hood and combustible material. Floor-mounted food service appliances listed for installation at lesser clearances shall be installed in accordance with its listing and the manufacturer s instructions. Appliances designed and marked, "For use only in noncombustible locations," shall not be installed elsewhere. [NFPA 54:10.12.1] 913.2 Clearance for Unlisted Appliances. Unlisted floormounted food service appliances shall be installed to provide a clearance to combustible material of not less than eighteen (18) inches (460 mm) from the sides and rear of the appliance and from the vent connector and not less than forty-eight (48) inches (1,219 mm) above cooking tops and at the front of the appliance. Clearances for unlisted appliances installed in partially enclosed areas such as alcoves shall not be reduced. Where clearances for unlisted appliances installed in rooms that are not partially enclosed are reduced, the combustible material or the appliance shall be protected as described in Table 5-3. [NFPA 54:10.12.2] 913.3 Mounting on Combustible Floor. (A) Listed floor-mounted food service appliances that are listed specifically for installation on floors constructed of combustible material shall be permitted to be mounted on combustible floors in accordance with its listing and the manufacturer s instructions. [NFPA 54:10.12.3.1] (B) Floor-mounted food service appliances that is not listed for mounting on a combustible floor shall be mounted in accordance with Section 913.4 or be mounted in accordance with one of the following: [NFPA 54:10.12.3.2] (1) Where the appliance is set on legs that provide not less than eighteen (18) in. (460 mm) open space under the base of the appliance or where it has no burners and no portion of any oven or broiler within 174 2010 CALIFORNIA MECHANICAL CODE